1. Field of Invention
The present invention relates to semiconductor devices and to methods for manufacturing semiconductor devices. More particularly, the invention relates to a semiconductor device that is reduced in size to a CSP (Chip Size Package) level, and to a method for manufacturing such a semiconductor device.
2. Description of Related Art
With further size-reduction of mobile telephones and information terminals in recent years, there are demands that smaller and lighter parts be mounted on printed circuit boards, and also semiconductor devices, such as LSIs, are required to achieve a high mounting density with a chip stacked layered structure at a CSP level. The related art, for example, Japanese laid-open patent application HEI 11-204720, discloses a stacked level CSP type semiconductor device, such as the one shown in FIG. 9, in which diced first and second semiconductor chips 51 and 52 are bonded onto a dielectric substrate 55 having mounting external terminals 53 through dielectric adhesive layers 57 and 59 with device forming surfaces thereof face-up. Electrode pads on each of the semiconductor chips are connected to wiring sections 58 on the dielectric substrate 55 using wires 54 formed of Au, Al or the like, which are then sealed by a resin 56.
Also, as disclosed in xe2x80x9cNikkei Micro Device,xe2x80x9d February issue, on pages 38-67, or xe2x80x9cElectronic Material,xe2x80x9d September issue, on pages 21-85 in 1999, wafer level CSP type semiconductor devices that integrate a wafer processing process and a package assembly process are provided. They may be provided such that, by reducing the number of parts, such as interposers, and the number of processing steps, compared to conventional CSP types that are manufactured from single chips, the manufacturing cost is lowered, and the total cost of packages is lowered.
The above-described stacked level CSP type semiconductor devices that use wires also attempt to provide further miniaturization. However, because a bonding area needs to be secured for the second semiconductor chip on the surface of the first semiconductor chip, it is difficult to reduce the size in a direction parallel (lateral direction) to the chip surface.
Also, because a bonding area needs to be secured as described above, the design of a chip in an upper layer and the design of a chip in a lower layer need to be modified, for example, even when a memory capacity is desired to be simply increased.
Also, due to the capability of the wire bonding apparatus, control of wire pitches and spatial control over the wire configuration are difficult. Therefore, such semiconductor devices are not suitable for multiple-pin packages of large size LSIs.
On the other hand, the wafer level CSP type semiconductor devices have an advantage in that they can be miniaturized to a general chip size as viewed in plan. However, since it is difficult to form stacked layers, the above described related art semiconductor devices have certain limitations in achieving a higher mounting density, even though such a higher mounting density is desirable.
The present invention addresses the circumferences described above, and provides highly reliable semiconductor devices that can achieve further miniaturization and higher mounting density. The present invention also provides methods for manufacturing such semiconductor devices.
To address the problems described above, a semiconductor device in accordance with the present invention provides a first semiconductor chip disposed facedown on a surface of a tape substrate, and a second semiconductor chip disposed face-up on a rear surface of the first semiconductor chip. The semiconductor device also includes:
a wiring pattern formed on the surface of the tape substrate;
a mounting external terminal formed on a rear surface of the tape substrate;
an external terminal of the first semiconductor chip connected to the wiring pattern;
a bonding pad formed on a surface of the second semiconductor chip;
a bonding wire that connects the bonding pad and the wiring pattern; and
a resin that seals the surface of the tape substrate, the bonding wire, and the first and second semiconductor chips.
With the semiconductor device described above, the first semiconductor chip is connected to the wiring pattern on the tape substrate with the external terminal, and the second semiconductor chip is connected to the wiring pattern on the tape substrate with the bonding wire. In this manner, the number of chips that use bonding wires is reduced, such that the degree of freedom and flexibility in designing the second semiconductor chip are enhanced. Also, a bonding area does not need to be secured on the surface of the first semiconductor chip, the chip size in the direction parallel to the chip surface (lateral direction) can be reduced, whereby further miniaturization and greater density of semiconductor devices can be realized. Also, control of wire pitches of bonding wires and spatial control of wire configurations become easier. Lowering of the reliability that may be caused by bonding wires can be reduced or avoided, and the reliability of semiconductor devices can be enhanced.
A semiconductor device in accordance with another aspect of the present invention includes a first semiconductor chip disposed face-down on a surface of a tape substrate, a second semiconductor chip disposed face-up on a rear surface of the first semiconductor chip, and a third semiconductor chip disposed face-up on a surface of the second semiconductor chip. The semiconductor device also includes:
a wiring pattern formed on the surface of the tape substrate;
a mounting external terminal formed on a rear surface of the tape substrate;
an external terminal of the first semiconductor chip connected to the wiring pattern;
a first bonding pad formed on the surface of the second semiconductor chip;
a second bonding pad formed on a surface of the third semiconductor chip;
bonding wires that connect the wiring pattern to the first bonding pad and the second bonding pad, respectively; and
a resin that seals the surface of the tape substrate, the bonding wire, and the first through third semiconductor chips.
Also, the semiconductor device in accordance with the present invention may further include a metal post formed between the external terminal and the surface of the first semiconductor chip, and a resin that seals circumferential areas of the metal post and the surface of the first semiconductor chip.
Also, in the semiconductor device in accordance with the present invention, the metal post may preferably be formed from a plated film or a metal ball.
Also, the semiconductor device in accordance with the present invention may further include a resin that seals circumferential areas of the external terminal and the surface of the first semiconductor chip. A surface of the external terminal may be exposed through the resin.
A semiconductor device in accordance with another aspect of the present invention includes a first semiconductor chip disposed face-down on a surface of a tape substrate, a second semiconductor chip disposed face-down on a rear surface of the first semiconductor chip, and a third semiconductor chip disposed face-up on a rear surface of the second semiconductor chip. The semiconductor device also includes:
a wiring pattern formed on the surface of the tape substrate;
a mounting external terminal formed on a rear surface of the tape substrate;
an external terminal of the first semiconductor chip connected to the wiring pattern;
an external terminal of the second semiconductor chip connected to the wiring pattern;
a bonding pad formed on a surface of the third semiconductor chip;
a bonding wire that connects the bonding pad and the wiring pattern; and
a resin that seals the surface of the tape substrate, the bonding wire, and the first through third semiconductor chips.
A semiconductor device in accordance with another aspect of the present invention includes a first semiconductor chip disposed face-down on a surface of a tape substrate, a second semiconductor chip disposed face-down on a rear surface of the first semiconductor chip, a third semiconductor chip disposed face-up on a rear surface of the second semiconductor chip, and a fourth semiconductor chip disposed face-up on a surface of the third semiconductor chip. The semiconductor device also includes:
a wiring pattern formed on the surface of the tape substrate;
a mounting external terminal formed on a rear surface of the tape substrate;
an external terminal of the first semiconductor chip connected to the wiring pattern;
an external terminal of the second semiconductor chip connected to the wiring pattern;
a first bonding pad formed on the surface of the third semiconductor chip;
a second bonding pad formed on a surface of the fourth semiconductor chip;
bonding wires that connect the wiring pattern to the first and second bonding pads, respectively; and
a resin that seals the surface of the tape substrate, the bonding wire, and the first through fourth semiconductor chips.
Also, the semiconductor device in accordance with the present invention may further include metal posts formed between the external terminals and the surfaces of the first and second semiconductor chips, respectively, and a resin that seals circumferential areas of the metal posts and the surfaces of the first and second semiconductor chips.
Also, in the semiconductor device in accordance with the present invention, the metal posts may preferably be formed from plated films or metal balls.
Also, the semiconductor device in accordance with the present invention may further include a resin that seals circumferential areas of the external terminals and the surfaces of the first and second semiconductor chips. Surfaces of the external terminals may be exposed through the resin.
A method for manufacturing a semiconductor device in accordance with the present invention includes:
preparing a first semiconductor chip having an external terminal on a surface thereof, and a second semiconductor chip having a bonding pad on a surface thereof, and preparing a tape substrate having a wiring pattern on a surface thereof;
disposing the second semiconductor chip face-up on a rear surface of the first semiconductor chip;
disposing the first semiconductor chip face-down on the surface of the tape substrate, and connecting by bonding the external terminal and the wiring pattern;
connecting the bonding pad and the wiring pattern by a bonding wire; and
sealing the surface of the tape substrate, the bonding wire, and the first and second semiconductor chips.
A method for manufacturing a semiconductor device in accordance with another aspect of the present invention includes:
preparing a first semiconductor chip having an external terminal on a surface thereof, a second semiconductor chip having a first bonding pad on a surface thereof, and a third semiconductor chip having a second bonding pad on a surface thereof, and preparing a tape substrate having a wiring pattern on a surface thereof;
disposing the second semiconductor chip face-up on a rear surface of the first semiconductor chip;
disposing the third semiconductor chip face-up on the surface of the second semiconductor chip;
disposing the first semiconductor chip face-down on the surface of the tape substrate, and connecting by bonding the external terminal and the wiring pattern;
connecting the wiring pattern to the first and second bonding pads by bonding wires, respectively; and
sealing the surface of the tape substrate, the bonding wires, and the first through third semiconductor chips.
A method for manufacturing a semiconductor device in accordance with another aspect of the present invention includes:
preparing a semiconductor wafer having a plurality of chip regions and first metal posts to take out electrodes formed on surfaces of the chip regions;
preparing first semiconductor chips having second metal posts to take out electrodes formed on surfaces thereof;
disposing the first semiconductor chips face-up on the chip regions in the surface of the semiconductor wafer;
sealing the top of the semiconductor wafer, the first metal posts, the first semiconductor chips and the second metal posts with a first resin;
removing the first resin by a specified amount to thereby expose surfaces of the first metal posts and the second metal posts, respectively;
disposing external terminals on surfaces of the first metal posts and the second metal posts, respectively;
dividing the semiconductor wafer to form second semiconductor chips that are respectively integrated with the first semiconductor chips;
disposing a third semiconductor chip having bonding pads face-up on a rear surface of the second semiconductor chip;
preparing a tape substrate having a wiring pattern on a surface thereof;
disposing the first semiconductor chip face-down on the surface of the tape substrate, and connecting by bonding the external terminals and the wiring pattern;
connecting the bonding pads and the wiring pattern by bonding wires; and
sealing the surface of the tape substrate, the bonding wires, and the first through third semiconductor chips with a second resin.
A method for manufacturing a semiconductor device in accordance with another aspect of the present invention includes:
preparing a semiconductor wafer having a plurality of chip regions and first metal posts to take out electrodes formed on surfaces of the chip regions;
preparing first semiconductor chips having second metal posts to take out electrodes formed on surfaces thereof;
disposing the first semiconductor chips face-up on the chip regions in the surface of the semiconductor wafer;
sealing the top of the semiconductor wafer, the first metal posts, the first semiconductor chips and the second metal posts with a first resin;
removing the first resin by a specified amount to thereby expose surfaces of the first metal posts and the second metal posts, respectively;
disposing external terminals on surfaces of the first metal posts and the second metal posts, respectively;
dividing the semiconductor wafer to form second semiconductor chips that are respectively integrated with the first semiconductor chips;
disposing a third semiconductor chip having first bonding pads face-up on a rear surface of the second semiconductor chip;
disposing a fourth semiconductor chip having second bonding pads face-up on a surface of the second semiconductor chip;
preparing a tape substrate having a wiring pattern on a surface thereof;
disposing the first semiconductor chip face-down on the surface of the tape substrate, and connecting by bonding the external terminals and the wiring pattern;
connecting the first and second bonding pads and the wiring pattern by bonding wires; and
sealing the surface of the tape substrate, the bonding wires, and the first through fourth semiconductor chips with a second resin.